Hatch Communications, also based in Leeds, will specialise in PR, event management and sponsorship.
Madeley resigned from his position after 13 years at Ptarmigan in February this year.
'I set up Hatch to get back to basics, to deliver new ideas and cutting-edge campaigns, from a hands-on senior team,' said Madeley.
Hatch has already been signed up by property and ports group Peel Holdings for the launch of its £50bn Ocean Gateway concept.
Madeley is joined by another former Ptarmigan employee, James Hickman, making up a five-strong team.
'Post-pitch, clients only see the senior team at parties, piling pressure on junior staff to deliver the promises the senior team made,' said Madeley.